1. Field of the Invention
The present invention relates to a Zero Insertion Force (ZIF) socket, and particularly to a ZIF socket with a guiding means.
2. Description of Related Art
U.S. Pat. Nos. 5,722,848, 5,489,218, and 6,371,786 each disclose a conventional ZIF socket. In addition, an article entitled xe2x80x9cSocket 462 (Socket A) Assembly, Low Profilexe2x80x9d was announced on the web: http://www.amp.com/productnews/pdf/1308344.pdf; also discloses a conventional ZIF socket. The conventional ZIF socket typically includes a base with a plurality of terminals received therein, a cover movably mounted upon the base and an actuator. The actuator includes an operating handle and an integral cam shaft sandwiched between the base and the cover. The handle is movable to rotate the cam shaft thereby driving the cover to move horizontally upon the base. Therefore, a Central Process Unit (CPU) mounted upon the cover moves together with the cover upon the base and pins of the CPU electrically connect with corresponding terminals of the ZIF socket. In addition, since the cam shaft is below and engages with the cover on a top face thereof, the cover has a slightly upward movement when the cam shaft rotates around. Referring to FIGS. 8 and 8A of U.S. Pat. No. 5,722,848, the cover forms a retention device (54) engaging with a restriction plane (64) of the base in order to prevent the cover from releasing from the base. However, since the moving distance of the cover correlates with the diameter of the cam shaft, the socket only provides small moving distance of the cover for little diameter of the cam shaft. If the moving distance of the cover must be increased, such must increase the diameter of the cam shaft and enlarge the upward movement of the cover which troubles the engagement between the retention device of the cover and restriction plane of the base, and affects the electrical connection between the pins of the CPU and the terminals of the socket.
Referring to FIGS. 11 and 12, U.S. Pat. No. 6,280,223 discloses a conventional socket 6. Similarly, the socket 6 includes a base 70, a plurality of terminals (not shown) received in the base 70, a cover 80 mounted upon the base 70 and an actuator 90 sandwiched between the base 70 and the cover 80. The actuator 90 includes a driving rod with a male screw (not shown). The driving rod of the actuator 90 is rotated and the male screw drive the cover 80 on a curved side surface to move horizontally in a longitudinal direction F as shown in FIG. 1. The socket 6 not only increases the moving distance of the cover 80, but also avoids an upward movement of the cover 80. In addition, the cover 80 includes a pair of beams 81 extending downwardly from a bottom face thereof and a pair of hooks 82 extending inwardly from bottom ends of corresponding beams 81. The base 70 includes a pair of slits 71 for receiving corresponding beams 81 and a pair of shoulders 72 for engaging with corresponding hooks 82 to prevent the cover 80 from moving in a transverse direction f. However, the planar friction between the shoulders 72 and hooks 82 requires a large driving force. In design, a sufficient gap B between the beam 81 and the base 70 is provided so that the hooks 82 may be successfully inserted into the slits 71. Such allows the cover 80 to move along the transverse direction f. In order to overcome the above issue, a metal flake (not shown) is frequently inserted into the gap B between the beam 81 and the base 70; such increases the friction between cover 80 and the base 70. Therefore, a large driving force is required to move the cover 80 upon the base 70.
Hence, an improved socket is required to overcome the disadvantages of the conventional socket.
Accordingly, one object of the present invention is to provide a socket preventing a cover upon a base from moving transversely.
Another object of the present invention is to provide a socket with a guiding means having small friction between a base and a cover for convenience to manipulation.
In order to achieve the objects set forth, a socket in accordance with the present invention includes a base, a plurality of terminals received in the base, a cover movably mounted upon the base, an actuator and a guiding means. The actuator is sandwiched between the cover and the base for driving the cover upon the base to move. The guiding means includes a pair of columnar guiding posts extending downwardly from a bottom face of the cover and a pair of guiding holes defined in the base for receiving corresponding guiding posts. When the cover is in an open position, the guiding posts are loosely received in the guiding holes; and when the cover is in a close position, the guiding posts are closely received in the guiding holes.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.